31.2 Overview

The Analog-to-Digital Converter (ADC) peripheral produces 10-bit results. The ADC input can either be internal (e.g., a voltage reference) or external through the analog input pins. The ADC is connected to an analog multiplexer, which allows the selection of multiple single-ended voltage inputs. The single-ended voltage inputs refer to 0V (GND).

The ADC supports sampling in bursts where a configurable number of conversion results are accumulated into a single ADC result (Sample Accumulation). Further, a sample delay can be configured to tune the ADC sampling frequency associated with a single burst. This is to tune the sampling frequency away from any harmonic noise aliased with the ADC sampling frequency (within the burst) from the sampled signal. An automatic sampling delay variation feature can be used to randomize this delay to slightly change the time between samples.

The ADC input signal is fed through a sample-and-hold circuit that ensures that the input voltage to the ADC is held at a constant level during sampling.

The selectable voltage references from the internal Voltage Reference (VREF) peripheral, are V_DD supply voltage, or external VREF pin (VREFA).

A window compare feature is available for monitoring the input signal and can be configured to only trigger an interrupt on user-defined thresholds for under, over, inside, or outside a window, with minimum software intervention required.